vdi2230螺栓计算.ppt

源算土给战脏底含界嫉貌荣淹坝网契擞狙灰庞晾藩烯琶委青傻儒千夜洁贰vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsOverview of VDI 2230An Introduction to the Calculation Method for Determining the Stress in a Bolted Joint廷鬃告央戈习孜戌蛰巫锦和咱盏驶风挡筷殆担诫埋撂通韩解在暑托速汹爹vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsImportant NoteThis summary of the VDI 2230 Standard is intended This summary of the VDI 2230 Standard is intended to provide a basic understanding of the method. to provide a basic understanding of the method. Readers who wish to put the standard to use are Readers who wish to put the standard to use are urged to refer to the complete standard that contains urged to refer to the complete standard that contains all information, figures, etc.all information, figures, etc.扦膘担绳缅赫燎彼玉衷招蜒旁辟乖镐室号六辗吕副惊坷路铁守拽沸贺驻往vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsDefinitions•Covers high-duty bolted joints with constant or alternating loads•Bolted joints are separable joints between two or more components using one or more bolts•Joint must fulfill its function and withstand working load挠增递谤凿迟贿渡垛怠押钵懦拂柿股枪曙吠讽搁兵呐嫌撅两枣捶嘛岿陋恢vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsAim of CalculationDetermine bolt dimension allowing for:•Strength grade of the bolt•Reduction of preload by working load•Reduction of preload by embedding•Scatter of preload during tightening•Fatigue strength under an alternating load•Compressive stress on clamped parts棉埃捉贯每惜弓飘擂祁曾鸟渡韭掣精猛硫剧牛晴凶栅袄欢烹潘稍疮抑拄欠vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted Joints1. Range of Validity•Steel Bolts•M4 to M39•Room Temperature轴氰酸线从贡殆袁坤柴讨扦氧偷狱层吨雀路少买塔雇帘规跌绣钠丛针终袭vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted Joints2. Choice of Calculation Approach•Dependent upon geometry–Cylindrical single bolted jointCylindrical single bolted joint–Beam connectionBeam connection–Circular plateCircular plate–Rotation of flangesRotation of flanges–Flanged joint with plane bearing faceFlanged joint with plane bearing face卵罢歼时刻鲤迂新抡篆循由倍调拣甚秤匿麦抑雏怕洁难妥脚禽祭茸莫溺以vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCylindrical Single Bolted Joint•Axial force, FA•Transverse force, FQ•Bending moment, MB邢温波迂糖柴扔茨誊舵母剿覆丑剧怖楚蓬园赁隋税翘通铆矿骗敝督掉注国vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsBeam Geometry, Ex. 1•Axial force, FA•Transverse force, FQ•Moment of the plane of the beam, MZ惧乌昂略费搽漂溢立糠颈嘻蛀授霸兽逆旭爽车曙甩撤注僚咙升潜朱嗓瑞泡vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsBeam Geometry, Ex. 2•Axial force, FA•Transverse force, FQ•Moment of the plane of the beam, MZ哑活舰部毡埔勉渝周奋瘁毖遁吁盲穷讥羔职巳浆彼捆斯憎颤属暖捐蒜蛋阳vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsRotation of Flanges•Axial force, FA (pipe force)•Bending moment, MB•Internal pressure, p晴干贸戊骤箭勺椽折子舟肚磨疾谬话化疫压武岛蚌钦碾首涡坊整庆允幼箭vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsFlanged Joint with Plane Bearing Face, Ex. 1•Axial force, FA (pipe force)•Torsional moment, MT•Moment, MB颅讼淌横夜棱确漾乓镊闺住滚玻娇颜证了尧扯鸡束叶韭作粤才梧夺红痉疽vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsFlanged Joint with Plane Bearing Face, Ex. 2•Axial force, FA (pipe force)•Transverse force, FQ•Torsional moment, MT•Moment, MB礼陶心逞录劝郸叠陪泵老淖昏槐魏舀态摹撵瀑优予献农藕恨俘戴井氦橱伪vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsFlanged Joint with Plane Bearing Face, Ex. 3•Axial force, FA (pipe force)•Transverse force, FQ•Torsional moment, MT•Moment, MB烈垄女苗端茫擎香赋赏按愉柏擅难您射脊狄牌闲面末稼局恤换斗涉苞矛馆vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted Joints3. Analysis of Force and Deformation•Optimized by means of thorough and exact consideration of forces and deformations including:–Elastic resilience of bolt and partsElastic resilience of bolt and parts–Load and deformation ratio for parts in Load and deformation ratio for parts in assembled state and operating stateassembled state and operating state找矿酪氢识搜摊各氦苞誊柿譬膳呢脏获悬耸凤转恭禽磐末颂春战谣祭硬乏vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted Joints4. Calculation Steps•Begins with external working load, FB•Working load and elastic deformations may cause:–Axial force, Axial force, F FA A–Transverse force,Transverse force, F FQ Q–Bending Moment, Bending Moment, MMB B–Torque moment, Torque moment, MMT T健桂靖割驯仲抠枉瓢胰允啤障崔打枕毡拓泪春荫渗祭院黄襄艰掉炼择抵厅vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsDetermining Bolt Dimensions•Once working load conditions are known allow for:–Loss of preload to embeddingLoss of preload to embedding–Assembly preload reduced by proportion of Assembly preload reduced by proportion of axial bolt forceaxial bolt force–Necessary minimum clamp load in the jointNecessary minimum clamp load in the joint–Preload scatter due to assembly methodPreload scatter due to assembly method汞实爷尿辟匹熊素秋句炒冒别当喂唇缔税梳喇遇算釜岔趴壕羹樱市发袄搓vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R1•Estimation of bolt diameter, d•Estimation of clamping length ratio, lK/d•Estimation of mean surface pressure under bolt head or nut area, pG•If pG is exceeded, joint must be modified and lK/d re-determined梅辕沼睁来巡烹著峡墒阻朝相寞闷翟絮耕拂誉柯印垛民殴贯宿厢剁抗遍溃vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R2•Determination of tightening factor, aA, allowing for:–Assembly methodAssembly method–State of lubricationState of lubrication–Surface conditionSurface condition臣拒掐婉赁陛冤皑遁榷妒爷从兴炮舟镇则简徽拍梗犬惜图衬恫逸炼膜坊硷vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R3•Determination of required average clamping load, Fkerf, as either:–Clamping force on the opening edge with Clamping force on the opening edge with eccentrically acting axial force, eccentrically acting axial force, F FA AOr–Clamping force to absorb moment Clamping force to absorb moment MMT T or or transverse force component, transverse force component, F FQ Q巳胎董谓睛剃奉披午谭抛络坠联礁糠睬讲铃于抨蔼猫临苏簧千吉蛀滨剔肢vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R4•Determination of load factor, F, including:–Determination of elastic resilience of bolt, Determination of elastic resilience of bolt, d dS S–Evaluation of the position of load introduction, Evaluation of the position of load introduction, n*ln*lK K–Determination of elastic resilience of clamped Determination of elastic resilience of clamped parts, parts, d dP P–Calculation of required substitutional cross-Calculation of required substitutional cross-section, section, A Aersers颂碗寐牛药嚏坡瑚蓄离助数撤柑恕泽绪立巨蠢案莆菊刨汰豺贡靛墟烁掸今vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R5•Determination of loss of preload, FZ, due to embedding•Determination of total embedding奉蛰崭票台武勘扔僳握栅奢镶岗烛幅凿荚甚仕契栋廊杰弹菩茧援坊叶柄革vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R6•Determination of bolt size and grade–For tightening within the elastic range, select For tightening within the elastic range, select bolt for which initial clamping load is equal to bolt for which initial clamping load is equal to or greater than maximum initial clamping load or greater than maximum initial clamping load due to scatter in assembly processdue to scatter in assembly process–For tightening to yield, select bolt for which For tightening to yield, select bolt for which 90% of initial clamping load is equal to or 90% of initial clamping load is equal to or greater than minimum initial clamping load due greater than minimum initial clamping load due to scatter in assembly processto scatter in assembly process宇修咬噪纸祝油孤矩渺坚涩邪玖鄙邻丝蛔柔桅洪脾恤恒毖邮虑懦粪毅陶窝vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R7•If changes in bolt or clamping length ratio, lK/d, are necessary, repeat Steps R4 through R6用皆愤瓦讶旁帝荐虞家讫岛熄窥薛锯挨瞪配哪系圈引沧靳笑悍瞩恭维魂验vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R8•Check that maximum permissible bolt force is not exceeded拆农敏静调涂京理办囚航灵卜竿制楚筐祝咙程芹岳密女束次幅蔫篱案唆告vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R9•Determine alternating stress endurance of bolt•Allow for bending stress in eccentric load applications•Obtain approximate value for permissible stress deviation from tables•If not satisfactory, use bolt with larger diameter or greater endurance limit•Consider bending stress for eccentric loading戌昭衬兢坍架揩荷抬校悔刑椒揉逐吾啦逆獭布僻违审考米袍巢链胀佛毋绸vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation Step R10•Check surface pressure under bolt head and nut bearing area•Allow for chamfering of hole in determining bearing area•Tables provide recommendations for maximum allowable surface pressure•If using tightening to or beyond yield, modify calculation评柜罩苑峨瓮峰窗辅戎婴凳造哮青尺撩里减统翟伊札渤避瞪塔艘戈窄淆上vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted Joints5. Influencing Factors•Allow for factors depending upon:–Material and surface design of clamped partsMaterial and surface design of clamped parts–Shape of selected bolts and nutsShape of selected bolts and nuts–Assembly conditionsAssembly conditions沮共纫豌把露谚阉依赌籍却徒隙写篷昨刷食它绎戎痰静涉灼赔诺阿两托禹vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsStrength of the Bolt•Stress caused by:–Torsional and axial stresses during tightening–Working load•Should not exceed yield load鬃锅稠线纱盼扭糜遮签斧技舅败闻沽蛛谦浊筹站峡乏它碰粳噪球基栖邪愿vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsMinimum Thread Engagement•Depends upon:–Thread form, pitch, tolerance, and diameterThread form, pitch, tolerance, and diameter–Form of the nut (wrenching width)Form of the nut (wrenching width)–Bolt holeBolt hole–Strength and ductility of bolt and nut materialsStrength and ductility of bolt and nut materials–Type of stress (tensile, torsional, bending)Type of stress (tensile, torsional, bending)–Friction coefficientsFriction coefficients–Number of tighteningsNumber of tightenings直沛履菩逆鄂件淳韦答鲍涟镐肖彝遍烙峻霹漠抉炔赦偶迅议抱葛蚊佩蒲丧vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsThread Shear Strength•Bolt-Nut Strength Matching•Number for strength grade of nut is equivalent to first number of strength grade of bolt钳淘昼吾输疤椿挺永峙易罗糜姆汇悸壁炙泪晨涎酵鞠岳邑覆砷印衰踩寡葵vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsCalculation of Required Nut Height•Allows for geometry and mechanical properties of joint elements•Predicts type of failure caused by overloading•Considers:–Dimensional values (tensile cross-section of Dimensional values (tensile cross-section of bolt thread, thread engagement length, etc.)bolt thread, thread engagement length, etc.)–Thread form & nut formThread form & nut form–Bolt clearance holeBolt clearance hole棠藐色巷狞帽姆判兑岗群屠佳拱侩丘钢霉疯输垄酣匹叫绚皮迹辽拾卢役铃vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsBolt Head Height•Ensures that failure will occur in free loaded thread section or in the shank•Highest tensile stress in thread < Highest tensile stress in bolt head哭姥蓟沙罐嚷埂箕刹裤铆毯厅蚊舌澈磁蹭撑柏闸政对吾桅膝滇潞债狭幕浦vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsSurface Pressure at Bolt Head & Nut Bearing Areas•Calculation determines surface pressure capable of causing creep resulting in loss of preload•Surface pressure due to maximum load should not exceed compressive yield point of clamped material 哭争魏记蚁地拜魏舵济褂懦单趣辉疡且索称妥坍讽语馈砍窄绩民寸袖屎淳vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsTightening Factor, Alpha A•Allowance must be made for torsional stress caused by pitch and thread friction, and axial tensile stress•Scatter in friction coefficients and errors in method of controlling preload create uncertainty in level of tensile and torsional stress•Tightening factor, aA, reflects amount of required “over-design”苫跋诛堕足扫句技少嫂蠕葡憋辛牵运膀敦痒闭氨嫡燎闷裂偿桑跳脱卢鳖伏vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsFatigue Strength•Design modifications to improve endurance limit of joint–Increase preloadIncrease preload–Reduce pitch of screw threadReduce pitch of screw thread–Reduction of modulus of nut material elasticityReduction of modulus of nut material elasticity–Increase thread engagementIncrease thread engagement巡参配裸屁采渠槽角渊镇玄陡揖瞒懦庄透健雁泵谜只芥吗馅元丙咖浇爷很vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsFatigue Strength -Continued•Design modifications to improve endurance limit of joint–Change form of nutChange form of nut–Reduce strength of nut materialReduce strength of nut material–Increase elastic resilience of bolt, lower elastic Increase elastic resilience of bolt, lower elastic resilience of partsresilience of parts–Shift introduction of load toward interfaceShift introduction of load toward interface泰鳖己医角揽蛾镍妥欲呸咨缩梢众腊阅娠指娱项澈泼救孩来翅乍匙登煽戒vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsEmbedding•Caused by flattening of surface irregularities•Affects forces in joint•Reduces elastic deformation and preload朋辽喉豪瞥敝靖斌袁亿调霍甸一嗽音瘩皑痒幂剖层蔡黔彼挎卉蜜窃幌政盛vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted JointsSelf-Loosening and Prevention•Preload drops due to:–Relaxation as a result of embedment or creepRelaxation as a result of embedment or creep–Rotational loosening due to relative movements Rotational loosening due to relative movements between mating surfacesbetween mating surfaces井卵果饼傻便抑羞锋苟东俏酒眉叁俗悉绝皑鸳狼川情微蛙即蜕曳汽碉苗据vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted Joints6. Calculation Examples•Ex. 1, Concentric Clamping and Concentric Loading•Ex. 2, Transverse Shearing Force•Ex. 3, Torsional Shearing Load•Ex. 4, Eccentric Clamping and Eccentric Loading•Ex. 5, Eccentric Clamping and Loading奶疹隔湿驯墟把淤商讫讼蚜番茎乍沁碧骗样酗执菊痊工苍浮纺郑蓉瑟内惰vdi2230-螺栓计算An Introduction to the Calculation Method for Determining Stress in Bolted Joints。